//封装倒计时逻辑函数
import { computed, onUnmounted, ref } from "vue"
import dayjs from "dayjs"
export const useCountDown=()=>{
    let timer=null
    //1,响应式的数据
    const time=ref(0)
    //格式化时间 为 xx分 xx秒
    const formatTime=computed(()=>dayjs.unix(time.value).format('mm分ss秒'))
    //2，开启倒计时的函数
    const start=(currentTime)=>{
         time.value=currentTime
        timer= setInterval(()=>{
            if(time.value==0){
                clearInterval(timer)
            }else{
                time.value--
            }
        },1000)
    }
    //组件销毁时清除定时器
    onUnmounted(()=>{
        timer&&clearInterval(timer)
    })
    return{
        formatTime,
        start
    }
}